TM 9-421 3-Inch Seacoast Gun Materiel: 3-inch (15-pdr.) Gun M1902M1 Mounted on 3-inch (15-pdr.) Barbette Carriage M1902 and 3-inch (15-pdr.) Gun M1903 Mounted on 3-inch (15-pdr.) Barbette Carriage M1903 1942-10-10
"In addition to a description of the 3-inch guns M1902 and M1903, this manual contains technical information required for the identification, use, and care of the materiel."
Digitized by AHEC (U.S. Army Heritage Collections) http://www.carlisle.army.mil/ahec/
"October 10, 1942."
"This TM supersedes ORD 1772, Description of 3-inch (15 pdr.)--gun M1903 and its breech mechanism, revised June 5, 1917; and in part ORD 1766, Instructions for mounting, using and caring for 3-inch (15 pdr.) gun and Barbette carriage M1902, revised October 30, 1913; and in part ORD 1701, Instructions for mounting, using and caring for 3-inch (15 pdr.) Barbette carriage M1903, revised May 8, 1916."
Updated by "Changes no. 1," (3 p.), dated 30 June 1943
Includes bibliographical references (pages 118-119) and index